^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * <linux/swait.h> (simple wait queues ) implementation:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include "sched.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) void __init_swait_queue_head(struct swait_queue_head *q, const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) struct lock_class_key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) raw_spin_lock_init(&q->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) lockdep_set_class_and_name(&q->lock, key, name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) INIT_LIST_HEAD(&q->task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) EXPORT_SYMBOL(__init_swait_queue_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * The thing about the wake_up_state() return value; I think we can ignore it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * If for some reason it would return 0, that means the previously waiting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * task is already running, so it will observe condition true (or has already).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) void swake_up_locked(struct swait_queue_head *q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) struct swait_queue *curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) if (list_empty(&q->task_list))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) curr = list_first_entry(&q->task_list, typeof(*curr), task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) wake_up_process(curr->task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) list_del_init(&curr->task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) EXPORT_SYMBOL(swake_up_locked);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * Wake up all waiters. This is an interface which is solely exposed for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * completions and not for general usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * It is intentionally different from swake_up_all() to allow usage from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * hard interrupt context and interrupt disabled regions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) void swake_up_all_locked(struct swait_queue_head *q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) while (!list_empty(&q->task_list))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) swake_up_locked(q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) void swake_up_one(struct swait_queue_head *q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) raw_spin_lock_irqsave(&q->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) swake_up_locked(q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) raw_spin_unlock_irqrestore(&q->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) EXPORT_SYMBOL(swake_up_one);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * Does not allow usage from IRQ disabled, since we must be able to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * release IRQs to guarantee bounded hold time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) void swake_up_all(struct swait_queue_head *q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) struct swait_queue *curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) LIST_HEAD(tmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) raw_spin_lock_irq(&q->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) list_splice_init(&q->task_list, &tmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) while (!list_empty(&tmp)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) curr = list_first_entry(&tmp, typeof(*curr), task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) wake_up_state(curr->task, TASK_NORMAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) list_del_init(&curr->task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) if (list_empty(&tmp))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) raw_spin_unlock_irq(&q->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) raw_spin_lock_irq(&q->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) raw_spin_unlock_irq(&q->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) EXPORT_SYMBOL(swake_up_all);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) wait->task = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) if (list_empty(&wait->task_list))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) list_add_tail(&wait->task_list, &q->task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) raw_spin_lock_irqsave(&q->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) __prepare_to_swait(q, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) set_current_state(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) raw_spin_unlock_irqrestore(&q->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) EXPORT_SYMBOL(prepare_to_swait_exclusive);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) long ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) raw_spin_lock_irqsave(&q->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) if (signal_pending_state(state, current)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) * See prepare_to_wait_event(). TL;DR, subsequent swake_up_one()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) * must not see us.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) list_del_init(&wait->task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) ret = -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) __prepare_to_swait(q, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) set_current_state(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) raw_spin_unlock_irqrestore(&q->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) EXPORT_SYMBOL(prepare_to_swait_event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) void __finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) __set_current_state(TASK_RUNNING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) if (!list_empty(&wait->task_list))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) list_del_init(&wait->task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) void finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) __set_current_state(TASK_RUNNING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) if (!list_empty_careful(&wait->task_list)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) raw_spin_lock_irqsave(&q->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) list_del_init(&wait->task_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) raw_spin_unlock_irqrestore(&q->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) EXPORT_SYMBOL(finish_swait);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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